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UNIVERSITY OF CALIFORNIA, 
COLLEGE OF AGRICULTURE, 



SUPPLEMENT, NO. 1, 



REPORT OF THE BOARD OF REGENTS. 



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JUL 36 1904 
D. ofD, 



THE PHYLLOXERA OR GRAPEVINE LOUSE, 

AND THE REMEDIES FOR ITS RAVAGES.* 



BY EUGENE W. HILGARD, 

Professor of Agriculture in the University of California, 



The name Phylloxera,t meaning leaf witherer, was originally given 
to a kind of plant louse which infests the European oak. We are 
now acquainted with sixteen species, of which only one, the Ph. vas- 
tatrix, of Planchon, affects the interests of man. The study of the 
others, however, has materially assisted in ascertaining the habits 
and life history of that one important species, which forms the sub- 
ject of the present paper. 

It was first observed in America in eighteen hundred and fifty-six, 
by Asa Fitch, of New York, on the leaves of native vines, and by 
him named Pemj^higns vitifoliis. Other names were subsequently 
applied by other observers to its various forms, until, about the year 
eighteen hundred and seventy, their identity was demonstrated by 
Lichtenstein, Riley, and others. 

All the earlier names and descriptions refer to the leaf-inhabiting 
and winged form of the insect. 

The Root Rot or '' Pourridie " of the vines, first mentioned as exist- 
ing in France about the years eighteen hundred and sixty-five and six, 
was shown to be due to wingless lice, in eighteen hundred and sixty- 
eight, by Planchon. But the identity of these root lice with those 
inhabiting the leaf-galls of certain native American vines, was for 
some time not even suspected. After attention had been called to 
their close resemblance, and to the fact that the Leaf Gall Louse 
descended to the root in winter, attempts Avere made, both in this 
country and in Europe, to transplant root lice to the leaves ; many 
of which were unsuccessful, in consequence of the failure of obser- 
vers to select suitable varieties of vines. Finally, in eighteen hun- 
dred and seventy and eighteen hundred and seventy-one, Rilej^ con- 
clusively proved the identity of the two types, by effecting the change 
of habit either way, on vines properly selected. He also showed 
that the all but universal failure of the European vines, as well as 
that of certain delicate native varieties in the Mississippi Valley, 
observed long since, was due to the attacks of the Root Louse. 

* Revision of "A Lecture on the Phylloxera or Grapevine Louse, delivered before the State 
Vinicultural Association, at San Francisco, November twenty-third, eighteen hundred and 
seventy-five," and forming Bulletin Number Twenty-three of the University of California, issued 
in January, eighteen hundred and seventy-six. 

t Pronounced as if spelled Jillo-xee-ra ; emphasis on xec. 



When, six years ago, I first examined the diseased vines in the 
Sonoma Valley, I was forcibly struck with the fact that I had handled 
vines precisely so circumstanced, thirty years ago, when my father, 
among the first, attempted the culture of Rhenish grapes in southern 
Illinois. 

From eighteen hundred and seventy, up to this time, the Phyl- 
loxera has spread in France with frightful rapidity, destroying 
wholly or partially thousands upon thousands of acres in the vine- 
growing districts. In eighteen hundred and seventy-one, the French 
Academy appointed a standing Phylloxera committee, whose reports 
and discussions often occupy a large portion of the weekly session. 
A prize of, first, thirty thousand, then sixty thousand, then three 
hundred thousand francs, has been offered for the discovery of an 
effectual and practicable remedy. But although hundreds have been 
brought forward, the prize has not yet been awarded. Meanwhile 
the existence and ravages of the insect have become obvious in Ger- 
many, Austria, Italy, Portugal, and Spain. Universal alarm has 
been created in these countries, and the literature of the subject has 
become exceedingly voluminous. 

In eighteen hundred and seventy-three, the French Government 
sent Planchon, a prominent scientist, to observe the Phylloxera in 
its native haunts in the United States ; it being now considered 
certain that the insect is at home on native American vines — which 
it does not materially damage in their wild condition — and has been 
imported into other countries with them. Planchon's observations 
and reports have fully confirmed, in all essential points, those pre- 
viously made by Riley and other American observers. Riley's 
observations, published chiefly in the reports made by him as State 
Entomologist of Missouri, are by far the most complete and reliable 
made in this country; and to his publications I am largely in4ebted 
for the material, and for the illustrations of the present paper. 

DESCRIPTION OF THE PHYLLOXERA. 

In most respects the Phylloxera resembles the common plant lice 
(Aphis), the main difference being that its wings lie flat, and overlap 
on the back, instead of being erected roof-fashion ; and that the three- 
jointed antennse have the terminal joint much the longest. All are 
quite small, the perfect winged form of the Vine Louse being about 
one twentieth of an inch in length. Its peculiar feature is the great 
variety of forms which it is capable of assuming under different cir- 
cumstances. Among them we distinguish two chief types, viz; the 
leaf-inhabiting one or Gall Louse, and the root-inhabiting or Root 
Louse. 

THE GALL LOUSE. 

The Gall Louse habitually infests the leaves of certain native 
grapes in the Eastern States, especially those of the Riverside and 
Frost Grape ( Vitis rijjaria and cordifolia). It covers the surface of 
the leaf with numerous fleshy swellings, of irregular shape, and 
often partially of a reddish tint. In them we find a wingless female 
louse, one twenty-fifth of an inch long. 



Fig. 1. 



Fig. 2. 




The Gall Louse. Fig. 1 — Vine leaf covered with galls. Fig. 2— Section of a gall and egg. 

gall louse. 



Fig. 3— Mother 



When the gall is filled with from two hundred to five hundred 
eggs, the mother louse dies. The eggs hatch in from six to eight days 
into active little larvae, of oval form, which soon leave the gall, go 
to the upper surface of downy young leaves, and insert their suckers. 
The latter consist of three fine threads, surrounded by a blunt and 
hairy sheath. The leaves soon begin to swell below, while a reddish 
down surrounds the louse above, gradually closing in. On suitable 
vines, the gall forms in a few days, and the grown louse begins to 
deposit eggs, fills the gall, and dies. The young lice not only attack 
the leaves, but also cover the tender shoots, and even the tendrils, 
with swellings. 

It has been calculated, that at the rate of five hundred eggs in 
each gall, the progeny of five or six generations would, if placed end 
to end, reach thirty times around the earth ; but under ordinary cir- 
cumstances so few survive that the damage done is comparatively 
trifling, and readily prevented by early attention. 

Towards the end of September the galls are mostly empty, the lice 
having gone to the roots to hibernate. 



THE ROOT LOUSE. 



The life history of the root-inhabiting type of Phylloxera is much 
more complex than that of the Gall Louse. 



Fig. 4. 




Fig. 5. 





The Root Louse. Fig. 4 — Young larva\ Fig. 5 — Adult (egg-laying) larvfe. Fig. 6 — Male insect. Fig. 7 — 
Vine root, with colonies of eggs and insects ou main root; sound rootlet; rootlets with swellings; dead 
rootlets; black. 

The newly hatched larvae of either are alike. Those of the Root 
Louse soon acquire tubercles over their surface ; these, however, are 
irregular, only skin deep, and sometimes absent. As the develop- 
ment progresses, two forms begin to differentiate themselves. One 
is of a somewhat pointed egg or pear-shape, and resembles the wing- 
less Gall Louse ; the other is of an oval form. 

The former-is the mother Root Louse; it remains on the root 
through life, sucking its juices, locating itself and its colonies by 
preference in crevices, creases, etc. At maturity, without sexual 
impregnation, each lays upwards of two hundred and fifty eggs, 
which on hatching again rapidly go through the same round of life. 



THE WINGED FORM. 



The oval form of the Root Louse larva is destined to become 
winged. 

Fig. 1. Fig. 2. 



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The Winged Phylloxera. Fig. 1 — Fertile variety, long-bodied; e, young insect with wing-pads. Fig. 2 — 

Sterile, short-bodied variety. 

• 

From the time it has achieved one third of its growth, the wing 
pads, or rudimentary wings, are visible. The individuals are more 
active than those of the wingless form, and are often seen crawling 
about; finally, in July* and August they shed their last skin, and 
take wing. The winged form has neither tubercles nor granules on 
its back. All are females ; a supposed male form, with shorter 
abdomen, proves to be merely a barren female. The perfect ones 
deposit from two to eight eggs M'here they alight, and then perish. 

The eggs are of two kinds : the larger, about two hundredths of an 
inch in length, are of the female sex; the others, about two fifths 
smaller, hatch into males; the tim^ required being about a fortnight. 

The sexual individuals thus produced are again wingless ; more 
than that, they are destitute of sucker, mouth, or alimentary canal, 
being evidently destined exclusively for the reproduction of their 
species. They are quite active and couple freely. 

These sexual females lay but one single egg apiece. This solitary 
egg, which is destined to hibernate, and hatch in Spring, produces 
again the ordinary mother Root Louse, which lays several hundred 
eggs, and is capable of repeating itself without sexual impregnation, 
for five or six generations. 

So far it would seem as though the production of the winged 
form at intervals were necessary for the renewal of the vigor of the 
species; and that, if its appearance could be prevented, or itself 
or its brood be destroyed, the Phylloxera might be almost exter- 
minated. 



* About that time there is usually a marked increase in the number of the insects, known 
as the " July invasion " in France. 



8 

Unfortunately, other observations have shown that nature has 
provided against the possibility of thus getting rid of the pest. 
Under circumstances not fully understood, the ordinary form of 
Mother Louse also at times performs the office of the sexual females, 
and lays the large solitary egg which is necessary for the rejuvena- 
tion of the insect. 

Such multiplicity of forms, of provisions for the perpetuity of the 
species, combined with such elasticity of habit, is not thus far known 
to exist in any other insect; albeit similar transformations have been 
observed in the species that inhabits the oak. 

IDENTITY OF THE GALL AND ROOT LOUSE. 

The identity, and convertibility into each others of the two princi- 
pal forms of Phylloxera, were long doubted. This was especially 
the case in Europe, where the conditions of the change of habit did 
not then exist. Many attempts to transplant the Root Louse to the 
leaves failed ; which is not surprising, when we consider that, as 
Riley showed, the insect does not form galls readily even on the 
Clinton vine, after having lived on the roots of other varieties for 
several generations. The leaves of the Clinton, and of its wild 
ancestor, the Riverside Grape, seem to be best of all adapted to 
the taste of the Gall Louse. In the South I have seen whole arbors 
of the Frost Grape iVitis cordifolia) thicklj^ covered with galls, so as 
to prevent its bearing altogether. Its roots, however, are scarcely at 
all infested during the growing season, but only serve as a retreat for 
hibernation or wintering. • 

On grape varieties whose leaves are not to its taste, the Phylloxera 
either forms no galls at all, or abandons them after making a trial, 
leaving "abortive" galls. In some cases it has been found living 
under the bark, above ground. Koehler (at Kloster-Neuburg), and 
Balbiani, succeeded in making the Root Louse live on the under sur- 
face of the leaves, in the third generation. The fact that the habits 
and mode of development of the insect depend very largelj^upon the 
nature of the vine, so that it will refuse to live on the leaves of some 
varieties, and decline the roots of others, is the key to the whole mys- 
tery of its changes of habit, whose importance was first fully shown 
by Riley. The failure to take ^l^is important consideration into 
account, explains the wide divergence in the results and conclusions 
of different observers and experimenters. More than this, it fur- 
nishes the most important cue to the prevention of the ravages of the 
insect in the vineyards of the future. 

On the European vine ( V. vinifera, which includes the Mission 
grape of California), leaf-galls have scarcely been known to be formed ; 
the attacks of the insect are altogether directed against the roots. 
The exact reverse is true of the native Riverside Grape of the East- 
ern States, from which the Clinton and related varieties are derived. 
Of the other American varieties, those descended from the Fox 
Grape ( Vitis lahrusca) of the Atlantic States, such as the Catawba and 
Isabella, are most liable to the attacks of the Root Louse; while 
those derived from the Summer Grape {V. jEstivalis), such as Nor- 
ton's Virginia Seedling, as well as the hybrids, differ greatlyin these 
respects, each requiring special experiment in different localities and 
climates, to determine their nature and powers of resistance. 

The Gall Louse is found occasionally on most of the grape varieties 



cultivated in the Eastern States. When placed on uncongenial 
foliage it descends to the roots. It was from the progeny of such 
lice that Riley obtained galls on the Clinton vine, which, with the 
Taylor, is most liable to its attacks. As, however, it refuses to live 
on the leaves of the European vine, it is scarcely known in France, 
save on imported American varieties. 

THE SPREAD OF THE PHYLLOXERA IN EUROPE. 

Since the Gall Louse never acquires wings, it can spread but slowly, 
by crawling. The same is true of the Root Louse, so long as it does 
not assume the winged form. It then migrates through crevices in 
the soil, or along the roots; or even over the surface of the ground, 
provided that the latter be not too sandy. Being unable to travel 
over or through sand, its development and progress is so checked in 
sandy regions as to render it almost powerless for harm. This cir- 
cumstance explains the fact that such regions have enjoyed almost 
complete immunity when adjoining ones were overrun with the 
plague. It is doubtless from this cause that the European grape has 
been successfully cultivated in the coast region of the Gulf of Mexico, 
while it has totally failed on the more generally clayey soils of the 
Western States. 

But the matter assumes quite a different aspect when the winged 
form makes its appearance. It is not known what percentage of the 
Root Louse progeny assumes this form under ordinary conditions; 
but it is certain that, at times, the winged insects appear in countless 
numbers in July and August. They do not seem to possess great 
powers of flight, but are so light and the wings so large in propor- 
tion to the weight, that the lightest breeze carries them along with 
ease. As to the objective point of their voyage, they do not seem to 
exert much selection, and the question as to the particular locality 
where the eggs are ordinarily intended to be deposited, has been 
much discussed. It is certain that, after alighting, they seek to lay 
their eggs in some furzy place, such as buds, or woolly leaves, or 
their axils, etc., since the eggs appear to be deposited indifferently 
in any such spot, whether on a vine or any other plant or tree. It 
is thus obvious why the spread of the insect has been so much more 
rapid in France — where vineyards extend uninterruptedly over 
extensive tracts — than in America, where they are mostly separated 
by intervening screens of woodland, on which large numbers must 
alight in their random flight, and, of course, perish for want of suit- 
able food. This circumstance conveys an important hint in regard 
to the prevention of the spread of the insect. But it is also obvious, 
from the facts just quoted, that the eggs may be conveyed from one 
place to the other, both in cuttings and in the material used for 
packing, as well as in numerous other ways. It is true that, under 
ordinary circumstances, the eggs hatch within a fortnight; but should 
cold weather supervene, they may remain dormant, as do the eggs 
deposited on the roots by the last generation of mother lice, which, 
together with the larva;, constitute the hibernating reserve. In 
such a case, of course, the insect would be ready to revive and flour- 
ish wherever the cutting should happen to be planted; and it is 
doubtless in this manner that it has found its way into many a vine- 
yard, and even across the sea. 



10 

The larvpe wintering on the roots are of a dingy color, and not 
easily seen; they are attached to the roots by strong suckers. Early 
in spring they revive, the eggs hatch, and the uninterrupted round 
of generation is resumed. 

INJURY DONE TO VINES. 

The injury ordinarilj^ done by the Gall Louse is comparatively 
insignificant, or easily rendered so by a little early attention — clip- 
ping off and destroying the infested leaves. It is only when neglected 
until it has developed for several generations, that it passes beyond 
control, and materially injures the crop on such varieties as are 
favorable to its development. 

It is quite otherwise with the Root Louse, whose presence is usually 
unsuspected until it has seriously injured one crop at least, and 
which, in any case, it is most difficult to reach. 

The first effect produced by the attack of the louse is a swelling of 
the tender white rootlets, which it prefers to the older and harder 
portions. In tlie center of these rounded, semi-transparent swell- 
ings, the puncture may be seen as a minute black dot, from which 
the rot commences after the insect deserts it for a new position. It 
has been thought that this prompt decay is induced by a secretion 
tliat the animal injects into the wound ; but it is more probably due to 
the inability of the deformed rootlets to undergo the normal process 
of transformation into dark, woody root fibers. 

As the invading army moves on, root after root is left behind to 
decay. During the first year, the vine usually shows but little 
appearance of disease, save that the fruit is slow to ripen, or matures 
but imperfectly. The lice being chiefly on the outlying rootlets, 
simply arrest the normal increase without harming the vitality of 
the vine. 

During the second year, the enemy rapidlj^ approaches the center, 
destroying all the finer rootlets. The vine appears sickly, with 
stunted, yellowish leaves, and fails to mature fruit. 

Some of the weaker vines succumb, so as to fail to put out leaves 
the third year. The stronger ones hold out through the season by 
the aid of two or three remaining roots, from the fact that the Root 
Louse, being somewhat dainty in its feeding, deserts a dying vine 
before it is completely exhausted, for " fresh fields and pastures new." 
This fact, the significance of which has been confirmed by direct 
experiment in France, shows that a weak or diseased condition of 
the vine is not, as has been supposed, a determining cause of the 
attack ; since the Louse prefers vigorous vines whenever it has the 
choice. Of course, however, a weak and old vine ordinarily suc- 
cumbs sooner than a strong and young one; and hence in the case 
of vines not constitutionally very well adapted to the nature of the 
Root Louse, the mere strengthening of its vitality by means of proper 
manures is sometimes sufficient to keep tliem in profitable bearing. 

The fundamental importance of a judicious selection of vines with 
.regard to their resistance to the Phylloxera, is thus obvious. 

Unfortunately, up to the i3resent time, nearly all the grape varieties 
planted in California belong to one of the most sensitive species — the 
"Old World" ( Vitis vinifera). It is true that some of tliese are some- 
what hardier than others; but none has so far shown any such degree 
of resistance to the Phylloxera, as to do more than to prolong the 



11 

life of the vine for a few years. The claim advanced bj^ some that 
the Mission grape is resistant, is based upon a confounding of the 
Mission with the wild native vine of California, which . indeed 
appears to be as indifferent to the attack of the insect as any of the 
wild grapes of the East. Other things being equal, the Mission vine 
is found to succumb about as readily as any other. 

The sweeping destruction that has followed the invasion of the 
French vineyards by the Phylloxera, is a matter of notoriety, and 
the sorrowful record need not be detailed here. When its presence 
was first recognized in the Sonoma Valley, it was naturally supposed 
that in a climate apparently so favorable to the development of the 
insect, its progress would be at least equally as rapid as in Europe. 
But from some cause not yet understood, its advance, though steady 
and inexorable, has been comparatively slow. Instead of twenty or 
thirty miles annually, its outposts have advanced only two or three, 
and sometimes much less, in each year. Again, while the ultimate 
fate of vineyards has been the same as everywhere else, and in the 
Sonoma Valley especially, hundreds of acres, once covered with 
vines, have been converted into wheat fields : yet on the whole it 
appears that the work of destruction has required a longer time ; 
that the vines have continued in profitable bearing two and even 
three years after the first attack, when growing on strong soil, and 
well cultivated. 

The last mentioned difference may be accounted for by the com- 
parative youth of the vines, and the freshness of the soils. But the 
slow advance made by the insect requires some explanation, not yet 
fully found in the facts thus fai* observed. I was indeed led to hope 
that -the winged form, through which chiefly the rapid diffusion of 
the pest is accomplished, might not be produced at all in California. 
Observations made during the present season have shown this hope 
to be fallacious, at least in so far that a considerable number of 
winged individuals was produced from infested roots brought from 
Sonoma, inclosed in jars filled with earth, under the care of Dr. J. S. 
Hyde, of Santa Rosa. Of these, a large proportion, especially of the 
earlier broods, was found to be of the short-bodied, and presumably 
infertile variety, figured above (p. 7). 

Observations made somewhat later (in September), by residents of 
the Sonoma Valley, have failed to reveal the presence of the winged 
form in the vine^^ards, and it still remains true that it has not as yet 
been seen abroad in California. And while there can be little doubt 
that closer observation, earlier in the next season, will reveal its pres- 
ence in the open air, yet the presumption remains, that the pro- 
duction of the winged form, and the spread of the plague through 
its agency, is in some way limited in the Californian climate, wljether 
simply as regards its numbers, or through the predominant produc- 
tion of the sterile variety, during the season wdien the regular winds 
would be most likely to carry tije minute flies to great distances. 
Were the winged form produced, at anj'' season, in such numbers as 
have appeared elsewhere, their presence could hardly have remained 
unnoticed by the many persons who have been looking for them 
during the past two years. 

Be that as it may, the unquestionable fact remains,' that since the 
insect spreads much more slowly in California than in France, it 
must be to that extent easier to check its progress; and that we may 



12 

succeed in doing so through means that have proved too expensive 
elsewhere. What these means are, I now proceed to discuss. 

COMBATING THE PHYLLOXERA. 

The problem to be solved in combating the Phylloxera is a diffi- 
cult one, not because of any tenacity of life in the insect itself, but 
simply on account of the difficulty of devising any means that will 
reach every one of the 'matted rootlets of a vineyard, over its entire surface, 
and to a deptli of from three to four feet ; with the additional conditions 
that the remedy must be cheap, not only as regards the material, hut cdso 
the work of application, and must not injure the vine materially. 

It is perfectly easy to devise thousands of compounds that will kill 
the insect, which is soft, jelly-like, and a few days after death is only 
represented by a thin, empty membrane hanging to its sucker. It 
is not nearly so easy to kill the eggs, which is of course of equal im- 
portance. Almost any substance or operation energetic enough to 
kill the eggs, will hurt the white rootlets more or less; and it is on 
these that the living insect is usually found in the greatest abun- 
dance, while the eggs are by preference deposited on older roots, 
whose bark and crevices afford them more protectioii. Both, and all 
of them, must therefore be reached if the insect is to be extirpated. 
The depth to which the roots reach varies with the soil and location, 
but is rarely less than three feet. In rows eight feet apart, the white 
roots usually interlock between the rows, so that the insect can 
migrate from one row to another without going above ground. 

Next to air, the cheapest medium for saturating the whole soil 
of a field to the minimum depth of three feet, is water; and the most 
obvious method for the destruction of the Phylloxera is, therefore, 

I. — SUBMEESION. 

I have already stated that the prize of the French Government for 
"an efficacious and practical remedy" for the ravages of the Phyl- 
loxera has not yet been awarded. Several of the remedies suggested 
fulfill one of these two indispensable conditions, and for a not incon- 
siderable class of localities, submersion fulfills both; but it must be 
applied to the infested vines for a sufficient length of time; i. e., 
for not less than thirty days in autumn, or even forty in winter. 
Wherever this can be done at a reasonable cost, the Phylloxera may 
be defied. The remedy, of course, is available to a limited extent 
only ; yet it has been applied, in France, in localities where steam 
irrigating machines had to be constructed for the purpose — because 
of the high connnercial value of the product of particular vineyards. 

The great length of submersion necessary to destroy the Root Louse 
and its progeny (as ascertained by experiment), renders it indispens- 
able to perform the operation while vegetation is in abeyance. It is 
found that submersion during the growing season, for a longer time 
than three days, materially injures the vine, while it does not sensibly 
interfere with the well-being of the insect. At the same time, when- 
ever the latter has assumed, or even approached, the wintering con- 
dition, it is prepared for the conflict with the elements, and much 
more difficult to destroy. The sooner after the cessation of vegeta- 
tion, therefore, the operation of submersion can be performed, the 
shorter will be the time required to exterminate the enemy. In 



13 

pervious soils, also, the effect will be produced in less time; showing 
that the reason why it takes so long to kill the louse is not so much 
its ability to resist drowning, as the circumstance that it takes a much 
longer time than is usually supposed, to fill the soil with water. 

In general, nevertheless, wet is decidedly injurious to the Phyllox- 
era. It is less troublesome in wet soils, and wet seasons sometimes 
check its progress materially. In connection with this point, it is 
important to remark, that experiment has shown light soils with a 
wet subsoil not to be as unfavorable to the vine as has often been 
supposed. The fact that several of our native vines are originally 
found on such soils only, naturally points to this conclusion, as well 
as to the grape varieties most likely to succeed in low ground. That 
such localities are most readily submerged, in case of need, is an 
additional weighty reason for locating vineyards on them, provided, 
of course, that the production of high quality wines is not intended. 

It would thus seem that the climate of California is exceptionally 
favorable to the rapid increase of the Phylloxera. Even our wettest 
winters cannot drown out the hardy eggs and hibernating larva?. 
On the other hand, our long dry season, which never fails, offers the 
insect a chance for uninterrupted development and indefinite multi- 
plicaftion, such as is scarcely to be found elsewhere. Add to this 
the circumstance that our prevalently heavy soils afford it additional 
advantages, by the facility with which it can travel from vine to 
vine and from vineyard to vineyard, through the crevices of the sun- 
cracked surface, and we have a concatenation of advantages on the 
side of the insect which warns us that, unless vigorous preventive 
measures are taken, the vineyards of the State must all ultimately 
succumb to its attacks. 

II. — SANDING. 

It has been proposed to employ the inability of the insect to travel 
or flourish in sandy soils, as a means for its destruction. But, plau- 
sible as this seems at first sight, it lacks the essential feature of prac- 
ticability on any but a very limited scale. To merely surround the 
stock with sand, may close to the insect this very convenient outlet; 
but it will not in the least interfere with its crawling to the surface 
through crevices elsewhere, nor stop its underground communication, 
through suncracks, and along the roots which interlock between the 
rows. Unless, therefore, the application of sand is carried to the 
extent of actually converting a heavy soil into a sandy one, but little 
good can be expected of it. That the expense of this operation would, 
in the vast majority of cases, be an effectual bar to its application, 
scarcely requires discussion; still it should be kept in view, since at 
times a mere diversion of the drainage may be sufficient to effect a 
beneficial change in the course of time. At all events, the principle 
may find an important application in circumscribing the spread of 
the wingless form, by means of ditches filled with sand. 

It has been proposed in the volcanic districts of southern France, 
to replace the mere arid sand by the volcanic sand or ashes, which 
can be readily obtained in many cases, and would, by its gradual 
decomposition, supply valuable soil ingredients, or plant food. 

The same objection that lies against the efficacy of sand placed 
around the stock of the vine only, applies equally to other impedi- 
ments put in the same place : such as plaster cast around and smeared 
with tar or other sticky substances ; or tarred sawdust similarly 



14 

applied. The Root Louse, wingless or winged, may choose this as an 
easy route when it is open ; but with its usual fertility in resources, 
it finds other outlets without much trouble, when that one is closed. 

III. — INSECTICIDES. 

The fact that any measures intended for the repression or destruc- 
tion of the Phylloxera must, in order to be effective, extend not only 
over the entire surface, but also into the depths of the soil as far as 
the rootlets of the vine reach, renders the use of insecticides, or poi- 
sons of any kind, both difficult and expensive of application. An 
immense number of these have been proposed, but a few only have 
proven of any practical value; partly because of the expense attend- 
ing their use, partly from the liability of the most effective ones 
among them to injure the vine as well as the Phylloxera, unless used 
with great caution. 

A list of all the remedies proposed would be a long one, and at the 
present time of interest only in so far, as it would show to inventors 
what has been already tried and found wanting. The essential con- 
ditions above enunciated, that any effective remedy against the Phyl- 
loxera must admit of being applied over the entire surface, and to a 
depth practically equal to nearly three feet, within reasonable limits 
of expenditure, at once throws out of consideration all but the cheap- 
est materials, or those capable of being readily diffused throughout 
this great mass of soil without losing their efficacy. The many mys- 
terious compounds, powders, etc., proclaimed from time to time as 
"Sure to kill the Phylloxera and not injure the vine," are but a few 
of many thousands of such that could be devised for the purpose, 
but no more practically useful than the well-known flea remedy, 
which was to be applied to the insect held firmly between the thumb 
and forefinger, compelling it to open its jaws for the introduction of 
the poison. 

Insecticide Solutions. 

Water naturally suggests itself as the cheapest vehicle through 
which a soluble insecticide can be introduced into every particle of 
the soil-mass to be treated. To a certain extent this principle can be 
usefully acted upon, and yet it is practically much less available than 
would appear probable at first blush. It has already been stated that 
when the ground can be kept flooded for a sufficient length of time, 
the Phylloxera can be, if not extirpated, at least kept in check, so as 
to be harmless. In such cases no insecticide, properly so called, is 
needed. When, on the other hand, a quantity of water sufficient to 
saturate so large a mass of soil has to be put on the ground by artifi- 
cial means, and at the same time charged with a more or less expen- 
sive insecticide, the cost readily becomes such as to exceed the value 
of the vineyard. This is largely due to the fact that the soil is a 
powerful absorbent of almost all substances soluble in water, thereby 
rendering them inactive toward animal life, for the time being. The 
same disinfecting property of soil that enables it to purify the foulest 
water filtered through it, without itself becoming offensive, also serves 
to render ineffectual a large proportion of any poison that may be 
introduced in watery solution. It is only after the soil has become 
saturated with it to a certain (very variable) extent, that a remain- 
ing portion can become effective. Hence, the amount needed of any 



15 

insecticide, when used in the soil, is very much greater than that 
whicli would be required if water were to be applied to the insect 
directly. A solution of carbolic acid, or a tea of the " Persian insect 
powder," that would be instant death to an insect sprinkled with it, 
becomes inodorous and harmless when filtered through a few inches 
of soil ; and the same is more or less true of all kinds of poisons. 

Again, it is quite useless to propose to " bare the roots of the vine" 
for any insecticide application on the large scale. In a bearing vine- 
yard the roots and rootlets form one matted mass all through the 
soil over the entire field, and it is at the remote ends that the insect 
forms its largest and most flourishing colonies. To bare all these is 
practically impossible, and would in any case involve an amount of 
labor incompatible with the profitable maintenance of the vineyard; 
especially if, in addition, the insecticide is to be carefully applied to 
all, and soaked in with water, as is mostly suggested by the proposers 
of such impracticable schemes. 

Gases. 

The use of poisonous gases to bo generated from substances intro- 
duced into the soil in small quantities was early suggested, and was 
followed up by the use of compounds capable of producing a slow 
generation, especially of sulpliuretted hydrogen ; a gas readily pro- 
duced from cheap materials, and instantly fatal to insects, even in 
minute quantities. Its effects on the latter proved to be all that 
could be desired ; but it was found to be almost equally fatal to the 
vines themselves, and was, therefore, soon abandoned. The same 
was found to hold true in regard to phosphoretted hydrogen and 
several other gases, whose cost alone would exclude them from use 
on the large scale. 

Bisulphide of Carbon. 

In the industrious search for a gas or vapor that would kill the 
insects without materially affecting the vine, the bisulphide of car- 
bon was early experimented upon. This substance is cheaply made 
by burning charcoal in sulphur vapor, in red hot iron or earthen- 
ware vessels. The vapor formed is very heavy and volatile, and 
requires very effectual arrangements for condensation. When pure 
it forms a colorless liquid, about one fourth heavier than water, of 
an aromatic and somewhat peppery odor, which is not disagreeable, 
and produces somewhat the effects of chloroform on the human sub- 
ject, but acts as quick as poison when inhaled by small animals. 
Ordinarily, however, it is contaminated with other sulphur com- 
pounds, which give it the offensive odor of rotten eggs and onions; 
and in this condition it is poisonous when inhaled, not only to ani- 
mals, but also to man. The very offensiveness of its vapor, however, 
is an excellent safeguard against accidents from poisoning. It is 
highly inflammable, and its vapor, when mixed with air, explodes, 
like that of petroleum spirit or alcohol. Since it boils but a little 
above the temperature of the hand, it evaporates very rapidly when 
poured on it, producing a feeling of intense cold ; when poured on 
damp earth, the latter soon freezes and becomes covered with hoar 
frost. The vapor so formed is three times heavier than air, and 
flows down visibly, like water, from the mouth of an open vessel 
containing the liquid. It is not sensibly absorbed by water, but like 



16 

all other vapors is condensed, and held to a considerable extent, by- 
dry earth. 

In the experiments at first made with this substance (which is used 
on the large scale for the extraction of sulphur from its ore, and of 
oils from oil-cake) it was found that, while it is very prompt in its 
action on the Phylloxera, it is also liable to injure and even kill the 
vine roots. For some time its use in the pure form was thought to 
be impracticable, and efforts were made to use it in its watery solu- 
tion, in combination with potash — the so-called " sulpho-carbonate " 
of potash. This method was measurably successful, and in some 
cases is still considered the best mode of application. But here, 
again, the necessity of using water to saturate so large a mass of soil 
proved a serious stumbling block, since it added to the already larger 
first cost of material, that of labor; to so serious an extent that the 
method could only be used to save very valuable vineyards. 

Returning to the direct use of bisulphide of carbon, it was soon 
discovered that there is a certain measure of dilution of the vapor, 
within which it is practically without any eff'ect on the vine, while 
still fully accomplishing its mission against the Phylloxera. This 
measure has now been ascertained by long and elaborate experiment; 
and by means of simple appliances that can be used by any intelli- 
gent laborer, the measure and mode of application of the liquid 
bisulphide to the soil of the vineyards can now be so gauged as to 
accomplish any desired object, from the mere repression of the insect 
while the vine is kept in bearing (culture treatment), to the complete 
extermination of both insect and vine. The latter course may be 
advisable when infested spots first show themselves in vineyards, 
with a view to stamping out the pest altogether. The former mea- 
sure will, as a rule, be adopted, where the infection has already 
become general, and the choice lies between it and the entire loss of 
the vineyard in the course of a few years. Experience ih France has 
shown that, when taken in time, the evil may be kept in abeyance 
at a comparatively trifling cost, by the use of the bisulphide, without 
interrupting the bearing of the vines. When farther advanced, the 
loss of one or several crops will result, even though the vines may be 
saved ; but there is a certain point beyond which it will pay better 
to replant and protect the young vines, than to attempt to rehabili- 
tate the old ones. 

Rules to be Observed. 

To accomplish these results, however, it is necessary to adhere 
strictly to the rules given as the result of the best practice, with only 
such modifications as may be commanded by the varying nature of 
the soils. These rules may be briefly formulated as follows : 

I. The application of the insecticide must be made only when the 
soil is fully moist, though not water-soaked. In dry soil, and in the 
dry and warm season, the vapor is rendered inert, partly by absorp- 
tion in the immediately surrounding soil mass, partly by evapora- 
tion to the surface. Moist soil absorbs the vapor but very slightly. 
In it, therefore, it can spread farthest, and is best protected from 
surface evaporation. To avoid the latter, also, the soil should not 
have been recently tilled. 

The failure to observe these fundamental conditions of success, 
has been the most frequent cause of disappointment, and has led to 
a current notion that the treatment is inapplicable to dry climates 



17 

like that of California and the south of France. On the contrary, 
the most emphatic reports of complete success now come to us from 
the Mediterranean departments of France, whose climate most closely 
resembles ours. 

II. Since it is the succulent white rootlets that are most liable to 
suffer from the effects of the insecticide vapor, the application is best 
made after these rootlets have hardened, in Autumn or in Winter, 
or before they have developed, in early Spring; even though, at 
these times, the hibernating and most hardy generation of the insect 
has to be dealt with. 

III. For the culture treatment, the carbon bisulphide must be 
used in small doses, of one sixth to one fourth fluid ounces each, 
injected into holes ten to sixteen inches deep,* which must be 
instantly closed on the removal of the " injector."t Of these holes 
there must be at least three per square yard of vineyard surface, 
regularly and evenly distributed; say ten to twelve thousand holes 
per acre. As an approximate measure of the speed and cost of such 
proceeding, it is stated that two ordinary laborers, working together, 
finish off about three hundred holes per hour. 

IV. When the " death treatment " is intended, the number of 
holes, or the dose of the insecticide, or both, are to be increased in a 
ratio that varies with the nature of the soil. Say, for example, fif- 
teen thousand holes per acre, and in each fifty per cent more of the 
liquid. 

V. In beginning the treatment of a badly infested vineyard, it is 
advisable to repeat the injections after the lapse of ten or fifteen 
days. When this is intended, smaller doses than the above may be 
used, and the second set of holes should be intermediate between 
the first. 

The cost of one "culture" treatment in France is given at eighty- 
seven and one half francs, or about seventeen dollars and fifty cents, 
per acre; that of two treatments, with diminished dose of the liquid, 
at one hundred and twenty-five francs, or say twenty-five dollars. 
This is on the basis of sixty cents daily for each laborer, and four 
and one half cents a pound for the bisulphide, wholesale — from two 
hundred and fifty to two hundred and eighty pounds per acre being 
used. 

From these data it will be easy to determine approximately, before- 
hand, the cost of treatment with bisulphide, under the prices for 
labor and material prevailing in this country. 

VI. The insecticide treatment of infested vines should always be 
accompanied by the use of appropriate manures, in order to 
strengthen the vitality of the vine and thus increase its resistance, 
both to the Phylloxera and to the influence of the insecticide. The 
nature of the manures required is indicated by the chemical analysis 
of the juices of the healthy and diseased vines. It has thus been 
shown that the change caused by the attack of the Phylloxera con- 

*The depth of the holes should be increased in proportion to the perviousness of the soil, 
which increases loss by surface evaporation. 

"("This injector consists of a hollow iron handspike, pointed, with cross-handle and foot-rest, 
for effective use. To this is attached a reservoir, containing about a quart of the bisulphide, 
closed at base by an adjustable piston-gauge valve, by whose action a dose of the liquid is ejected 
from an opening near the point of the spike, when the latter is withdrawn from the hole. The 
tool for closing the latter is a solid iron handspike with a hollow cone or cup at the lower end. 

3'" 



18 

sists mainli^ in the diminution of the potash and albumen normally 
contained in the juice; also in that, instead of crystallizable sugar, 
the abnormal juice contains chiefly or wholly the variety called 
glucose. 

It was thus indicated that manures rich in potash and nitrogen, 
should be used, in order to enable the plant to maintain as nearly as 
possible the normal condition. Experience has abundantly justified 
this important conclusion. In numerous cases (probably in soils 
poor in potash and nitrogen, or from their sandiness not very favor- 
able to the Vine Louse) the use of these manures alone has so far 
improved the condition of the vines, as to neutralize the injury done 
by the insect, and restore them to their usual productiveness. In all 
cases, when the vines were not too far gone, their condition has been 
materially improved by the application. 

Potassic manures appear to exert the most decided effects ; and 
fortunately, the material which most cheaply supplies this important 
substance {Kainite) can now be readily obtained in commerce. 
Wood ashes, wherever obtainable, are of course equally well adapted 
to the purpose. 

On strong clay or adobe soils a dressing of quicklime will produce, 
for the time being, an effect similar to that of the direct application 
of potash manures, while at the same time it will facilitate tillage, 
and impart to the soil the Cjualities of those on which the best of 
wild vines are usually found. 

Next in efficacy to potassic manures are those supplying nitrogen, 
especially in the form of ammonia.. In selecting these it should be 
borne in mind that most of the compound ammoniacal manures of 
commerce contain this substance in connection with phosphates. 
These, however, in general, are of subordinate interest in the case 
before us, as proven by experiment as well as analysis. It is obvi- 
ously best to throw whatever outlay can be afforded in the direction 
where it will do the most immediate good, by supplying the ingre- 
dients chiefly needed. The commercial sulphate of ammonia, now 
abundantly and cheaply obtained from gas-water, seems to be one of 
the most available materials for the purpose. All refuse animal 
matter answers the same object; and so, to a considerable extent, 
does Chilian saltpeter. 

As a matter of course, stable manure answers this, as it does almost 
every other purpose for which manure is wanted. The only question 
is, how to get enough of it — the problem which agriculturists have 
been trying to solve from the most ancient times to the present. 

Since everything that tends to strengthen the vitality and develop- 
ment of the vine, increases its power of resisting the attacks of the 
enemy, and correspondingly increases its ability to produce crops 
despite of the drain upon its juices, thorough and careful culture at 
the proper time is to be considered as one of the necessary elements 
of success in the struggle. This point is not made very prominent by 
the French Commission, because French cultivators are habitually 
diligent in this respect. But as this is far from being the rule on 
this side of the Atlantic, an express admonition can hardly be deemed 
superfluous. Thorough tillage is cheaper than manuring, when the 
manure has to be bought; and on our unexhausted soils it will to a 
large extent replace the latter. That deep tillage is especially 
important in California, on account of the long dry season, hardly 
requires discussion. 



19 

The question as to whether it will noiv pay to manure and cultivate 
the vinej'ards thoroughly, I will not discuss at length. The present 
state of our viniculture is in so many respects anomalous, that it can 
hardly be taken as a safe basis for estimates of what may be, even a 
few years hence. 

In the natural course of things California can hardly fail to become 
one of the foremost grape-growing countries of the world, since it 
possesses all the natural advantages for this branch of industry that 
can be imagined. The agriculture of all countries must, after a short 
period of exhaustive culture, be carried on on the basis of returns to 
the soil in the shape of manures. Even our Western and Southern 
States are fast coming to this, and California will have to do so in 
her turn ; first commencing with such crops as from their high value 
and sensitiveness as to quality, will best pay for high culture. The 
grape crop is preeminently one of these. 

In any case, the question will soon arise, whether owners of vine- 
yards can better afford to manure, or to lose their investment. Those 
who are now suffering from the ravages of the Phylloxera, will 
doubtless be able to throw some light on the question. 

There are two other modes of applying the carbon bisulphide, ^ 
that have been measurably successful in practice, and may present 
advantages in certain cases. 

One is, to absorb the liquid bisulphide into porous bodies, such as 
wood or clay, which are then buried in the soil near the vines. 
From them, a slow diffusion of the vapor takes place, sufficient to 
kill the parasites, but not to injure the vine roots. The most success- 
ful application of this principle is that of the "Cubes Rohart" or 
Phylloxera bricks ; prisms of half-baked, porous clay, filled with the 
liquid insecticide under pressure, and then coated with glue to pre- 
vent evaporation, until the glue is softened by the moisture of the 
soil. The operation of introducing these Rohart bricks into the 
soil, being the same as in the case of the liquid bisulphide, it is 
obvious that the entire expense of their manufacture is in excess of 
the cost of the use of the liquid insecticide ; the only advantage 
being that in no case can the vine roots be injured by the very slow 
evolution of the poisonous vapor. But, since experience has shown 
that the same result can be achieved by an adequate subdivision of 
the liquid doses, there is little probability that any such indirect 
mode of application will hereafter be preferred. 

The sulpho-carbonate of potassium has already been mentioned as 
one of the forms in which bisulphide of carbon may be applied. It 
being rendered soluble in water by combining it with sulphide of 
potassium (liver of sulphur.) The preparation of this com- 
pound is somewhat complex, though not very costly. It ranks next 
to the carbon bisulphide as a cheap and effective insecticide, but it 
is not quite as harmless to the vine roots, and its application, by 
means of water, is more laborious and costly. But, there are cases 
in w^hich it is nevertheless preferable. It sometimes happens that 
in very pervious soils, in which the bi-sulphide must be injected to 
a considerable depth, the insects clinging to the most superficial 
roots are not killed, in consequence of too ready access of air, by 
which the poisonous vapor is so diluted as to be ineffectual. In 
such cases, w^ater charged with about one eight-thousandth of its 
weight of the sulpho-carbonate, is an effectual and comparatively 



20 

cheap surface application, the soil being moistened with it to a depth 
of six to ten inches only. It is therefore very desirable that this 
compound, also, should be accessible to vine-growers. 

Other Insecticides. 

Of other insecticide applications that may be available and useful 
in certain cases, it will suffice to mention a few that have proved to 
be of some practical utility. 

Coal tar and crude carbolic acid have from the first been promi- 
nent among the antidotes suggested ; and while they have failed to 
perform all that might be desired, there can be no doubt that they 
may advantageously be used as repressive agents, to impede or pre- 
vent the migration of the wingless insect over the surface of the 
ground, as well as the flight of the winged form. These objects are, 
to a considerable extent, accomplished by sprinkling the surface of 
the ground thickly with sawdust, or similar material, previously 
impregnated with tar, or tar water ; the operation to be repeated from 
time to time, as the odor evaporates; a somewhat thicker dressing of 
the same material to be applied around the stock of the vine. Applica- 
tion of the same to the exj^osed surface roots does not seem to pay for 
the additional trouble by increased effects ; and too direct contact of 
the tar with the rootlets injures or kills the latter. 

Soot may be similarly used ; its effects are advantageous in other 
respects, and there is no danger of injury to the vines. 

Gas lime, from the purifiers, must be used with great caution. Its 
effects, due to the combined action of the tarry substances and of 
sulphur compounds (the latter giving off "sulphuretted hydrogen" 
inthe soil) are so energetic, that the vine may easily suffer as much 
therefrom as the Phylloxera. It may be applied mixed in moderate 
quantities with the tarred sawdust, or scattered over the surface spar- 
ingly by itself. 

Sidphuretted hydrogen, generated in the soil on the application of 
the sulphur compounds of some of the metals, etc., is a very ener- 
getic insecticide, but scarcely less dangerous to vegetation, unless its 
action is made very brief It is instant death to insects, while plants 
recover, after some time, from the effects of a brief exposure to its 
action. Hence its availability for the destruction of the Phylloxera, 
if used with great caution. So much permanent injury, hovvever, 
has resulted from the improper and excessive use of sulphides, that 
their application by inexperienced hands is mainly useful for the 
purpose of exterminating the insect in ground which is to be re- 
planted in vines, after the removal or death of infested stocks. Where 
the residues of soda manufactories are available, this can be done 
at a cost not exceeding that of transportation and application. Oth- 
erwise, suitable materials are not ordinarily obtainable at a low cost, 
apart from the gas lime, already referred to. 

PREVENTIVE MEASURES. 

Whatever may be the conclusion reached in respect to the profit- 
ableness of maintaining or restoring badly infested vineyards, there 
can be no possible doubt in regard to the action to be taken in dis- 
tricts not yet invaded. Since the attack always proceeds from a few 
well defined and easily recognized centers, a close and unremitting 



21 

watch must be kept over every vineyard in each region, in order to 
detect the invasion in its first beginnings; when a few pounds of the 
insecticide, coupled with a few hours of intelligent work, will at once 
put an end to the immediate danger of farther spreading of the pest. 
The transportation of vineyard products, and especially of cuttings 
from infested regions, should be closely guarded, and a preliminary 
disinfectant treatment with bisulphide vapor applied in any case of 
doubt. Wagons, agricultural implements, and even the clothes of 
persons working in infested vineyards, may carry the eggs of the 
insect from one vineyard to the other, or from infested portions of 
one and the same to the sound portion. 

It is thus obvious that sanitary regulations similar to those prac- 
ticed in respect to other contagious diseases, should be established 
and enforced in regard to the "Phylloxera pest. No one should be 
allowed to disregard or consider himself exempt from such regula- 
tions, and their infringement should be visited with the same repro- 
bation or penalty that would attach to the violation of the sanitary 
rules regarding smallpox or yellow fever. Above all is it needful 
that no one should be permitted to hide the fact that his premises 
are infested, since the precautions adopted for the common welfare 
would thus be rendered nugatory. Any sale or pecuniary transac- 
tion based upon a wilful concealment of such fact, would be morally, 
and should be legally, considered as tainted with fraud. 

It is now known that the infested region forms a broad belt across 
the State, from Sonoma to the Sierras, the northern limit being from 
the head of the Sonoma Valley proper, below Bennett Valley, across 
to Yountville, in the Napa Valley, and thence to the neighborhood 
of Placerviile; while the southern limit seems to be, thus far, the 
north shore of the bay, the Sacramento and American Rivers, Amer- 
ican River in the valley; in the foothills, south of the same. But 
one infested spot is known north of Yountville, and this there is 
reason to hope will be promptly stamped out. It is for those living 
outside of the above limits to see that the enemy is not carried into 
their vineyards, either by carelessness or intentionally, and with the 
aid of the measures suggested above this can unquestionably be done. 

"Eternal vigilance" will be found in this case, as in others, the 
cheapest price at which exemption from the pest can be purchased. 
Any vine showing symptoms of disease should be at once examined, 
especially on its outlying white rootlets, in order to detect the swell- 
ings that form the mark most readily recognized by the naked eye. 
Upon these, also, the minute yellow insects are most easily seen. An 
infested spot will soon appear as a basin-shaped depression in the gen- 
erally leafy surface of the vineyard. Of course, such spots may result 
from other causes, such as poor or shallow soil, lack of drainage, etc. 
In their examination for the presence of the Phylloxera, not only the 
vines within the depression should be examined, but also those 
located two or three rows beyond, since, as already stated, the insect 
prefers strong and healthy vines for pasture, and will entirely abandon 
weak ones long before they die. 

Any good eye can detect the characteristic ma,rks of the Phylloxera, 
when once accustomed to the search; but by the aid of the lens, and 
a comparison with the figures given above, little doubt can be left in 
most cases. In case of doubt, specimens sent to the University will 
be examined and reported upon. But in their transmission great 
care should be taken to prevent an accidental scattering of the con- 



22 

tents of the package. A few rootlets, or root fragments, should be 
inclosed in a small vial, filled with moist earth; this, well stoppered 
and then inclosed in a bored wooden block, forms a safe package, 
which can be sent by mail at a trifling expense. 

OUR FUTURE VINEYARDS. 

However important it may be to save the vineyards now existing, 
the problem of rendering those to be planted hereafter, proof against 
the attacks of the Phylloxera, deserves no less serious consideration. 
Fortunately, the thorough studies made in the East and in Europe 
on this subject, show us a plain and inexpensive way to the attain- 
ment of this great-desideratum 

The fact that the Root Louse does not attack the roots of certain 
grape varieties, while the Gall Louse is equally unable to live on the 
leaves of others, at once suggests the grafting of the latter varieties 
upon the former as an effectual remedy against the depredations of 
either form of the Phylloxera. 

The practical application of this principle has already been widely 
tested, both in the East and in Europe; and in most cases with the 
happiest results. 

Cases of failure have also been reported, and these appear to be redu- 
cible to two classes. The first and most numerous is that which is 
referable to the inattention of observers to the necessary precaution 
of preventing the scion from casting roots of its own, By grafting 
sufficiently above ground, instead of on the root, as is the usual 
practice in grafting grapevines. 

A second but less numerous class of failures seems to have resulted 
from actual differences in the kind and degree of susceptibilities of 
the varieties used, from that experienced in other localities. At first 
sight this appears an alarming result; but it loses much of its serious- 
ness when we reflect how strongly the nature of the soil, as well as the 
accidental character of a season, may have influenced both the original 
determination of the character of the vine in relation to the Phyl- 
loxera, and the subsequent contradictory experiments. It is contrary 
to all experience to suppose that the vine, in its relations to the Phyl- 
loxera, should act differently from what it — as well as all other grafted 
stocks and scions — is known to do as regards every other peculiarity. 
The facts before us, however, are sufficient to warn us that before 
determining upon the j^-roper stocks and scions for our vineyards, 
somewhat extensive and prolonged experiments should be made ; 
and that not only at one locality in the State — least of all at one 
where, as is the case at Berkeley, the grape does not succeed under 
ordinary circumstances — but in each of the chief vine-growing dis- 
tricts of the State. In the meantime, only such stocks as have proved 
to resist the Phylloxera most completely, under all circumstances, 
should be chosen as the basis of new vineyards. 

The following table, taken from Professor Riley's reports, exhibits 
the result of experience in the Eastern States concerning the relative 
powers of resistance of the most important grape varieties, to the Root 
Louse. The relative "importance" indicated in the table, refers, of 
course, to the general estimateof the wine-making qualities and hardi- 
ness of the varieties, in the climate and soils of the Western States — 
especially Missouri, Illinois, and Ohio. For California these estimates 
may require modifications, which must be determined by experience. 



23 

TABLE OF GRAPE VARIETIES. 

KXIUUrriNG TllKIR RKSISTANCE TO THE PIIYLI.OXKR A. 

A. — Recommended for use as stock to graft on, because not liable to the Hoot Louse. 

1. C!oiifoi\l, 5. Norton's Virginia. 

2. Clinton, 6. Reritz, 

3. Herbeniont, 7. Cyntliitiua, 

4. Gunuinghani. 8. Taylor. 

jy. — Varieties to graft on the above — vcrj/ liable to the Root Louse. 

Of Fii'st Importance: 

1. Catawba, 4. Wilder, 

2. lona, 5. Goethe, 

3. Delaware, 0. All Etiropean Grapes 

(including Mission). 
Of Secondary Importance : 

7. Ives, 9. Hartford Prolific. 

8. Maxatawney, 

Fortunately, the two varieties most highly esteemed in the Missis- 
sippi Valley for their wine-making qualities and hardiness, are also 
first among those enjoying immunity from the Root Louse. _ It might 
thus fairly become a question, whether some of these American varie- 
ties should not bodily be substituted, to some extent, to the varieties 
of the European stock, now almost exclusively cultivated in Califor- 
nia. But there can hardly be a question as to the propriety— not to 
say necessity — of using these hardy varieties as stocks whereon to 
graft the more delicate ones we may wish to retain on our list. That 
the Concord and Clinton, as well as the Catawba, Isabella, and other 
American varieties, make a vigorous growth in California, experience 
has already demonstrated, perhaps at the cost of introducing the 
Phylloxera into the vineyards of this coast. We may as well now 
try to profit by the experience so dearly bought; the more as the Mis- 
sion grape is not, assuredly, in itself a desirable wine grape. 

Among the resistant stocks most readily available to California 
grape growers, the native wild grape, Vitis^ Calif ornica, deserves 
earnest attention. In its botanical characters it stands near the wild 
species from which the Clinton and Taylor are derived ; and while it 
does not seem to harbor naturally either variety of the Phylloxera, 
experiments made by planting it among infested vines, seem to show 
that, although some insects will migrate and attach themselves to 
its roots, it does not suffer in any sensible degree from this attack. It 
should be understood that under similar circumstances the roots of 
the Clinton and Taylor are also visited by the insect, but without 
injuring vitality. Experiments as to the facility of propagation, 
adaptability to grafting with the most desirable varieties _ of the 
European stock, etc., are now in progress, both at the experimental 
grounds of the University, and by private parties, so that certainty 
on these points will not be long delayed. Naturally, also, the Cali- 
fornian wild grape seems to promise well for development into a 
desirable claret wine grape, and experiments on all these points 
cannot be too widely repeated. 

The expense of using grafts in planting out vineyards is, of course, 
somewhat greater than when simply rooted cuttings are set out. 
But this is a trifling consideration when an investment which is to 
last for thirty or forty years is at stake. Grafting the vine above 



24 

ground is not by any means so precarious an operation as is supposed 
b}'' many, and may be accomplished successfully in a variety of ways, 
the most important of which are: 1. Grafting the rooted cuttings; 
when carefully done, especially using canes of the same diameter, in 
good seasons but a small percentage fails. 2. Grafting by inarching; 
this is applicable to older vines, and is done by inserting both ends 
of the scion, sharpened, into cuts made in the stock so as to cause 
the former to be elastically retained. The scion so placed rarely 
fails to " take," and the stock, and scion can be severed at leisure 
between the joints. 3. Another mode, strongly recommended in the 
West, is to plant two cuttings (stock and scion) about a foot apart, and 
as soon as the canes of the first year's growth have sufficiently 
ripened, join together firmly by smooth-cut surfaces, and after they 
have united, cut the connection between the scion and its root. This 
mode is of course infallible, as it can be repeated should the first 
joint fail to " take." 

Either mode of proceeding, of course, to be successful requires 
precautions which I cannot here consider at length. One essential 
point, however, is that cleft grafting is ill adapted to American caues 
at least, and probably to all. 

FACILITY OF PROPAGATION. 

An important point to be considered in this connection is the 
facility Avith which the several stocks and scions recommended may 
be propagated in the cheapest manner, i. e., by rooting cuttings; it 
being obvious that propagation, by layering, if necessary, would 
materially increase the first cost of a vineyard. On this subject the 
subjoined table (furnished by Mr. George Husman, the veteran 
Missouri viniculturist, to Professor Riley), will convey important 
information : 

TABLE OF GRAPE VARIETIES. 

EXHIBITING FACILITY OF PROPAGATION BY CUTTINGS. 

A. Practically not propagablt hy Cuttings; must be Layered. 



1. 


Herman, 




3. 


Cynthiana. 


2. 


Nortou's Virginia, 










B. 


Quite difficult to propagate from 


Cuttings. 


4. 


Herbemont, 




7. 


Rulander, 


5. 


Cunningham, 




8. 


Louisiana, 


6. 


Devereux, 


C. Cuttings, root with tolerable 


9. 

ease. 


Delaware. 


10. 


Eumelan, 




12. 


Maxatawney. 


11. 


Creveling, 


D. Cuttings root easily. 






13. 


Hartford Prolific, 




20. 


Rogers' Hybrids (Goethe, 


14. 


Telegraph, 






Massasoit, Wilder, Lind- 


15. 


Ives, 






ley, Agawam, Merrimac, 


16. 


Concord, 






Salem, etc.). 


17. 


Catawba, 




21. 


Arnold's Hybrids (lietween 


18. 


lona. 






Foreign and Clinton.) 


19. 


Diana, 


E. " Boot like Willows." 






22. 


Clinton, 




23. 


Taylor. 



• 25 

It will be observed that here, again, the Clinton and Concord stand 
among those offering the greatest advantages ; the former, with the 
Taylor, preeminently so. It would thus seem that, so far as experi- 
ence goes, these two varieties offer the best prospects for the solution 
of the important problem before us. 

Of late the propagation of vines by means of seed has been consid- 
erably discussed and experimented upon. It has been contended by 
some that the attack of the Phylloxera is due, not to its introduction 
from America, but to a gradual weakening of the vitality of the vine 
by long 'continued cultivation, and especially propagation by cut- 
tings only. 

While the array of facts carefully observed and compared, seems 
conclusive against this view (which is most especially inapplicable 
to the American grape varieties but lately taken from the woods, and 
yet quite as sensitive to the attack of the insect as any of the 
European varieties), yet it is indisputable that vines grown from cut- 
tings offer points of weakness not present in a normally grown seed- 
ling. The root system of the latter is more copious, more widely 
and deeply spread, and its crown does not offer a point of weakness 
and a favorable locality for a nidus of the attacking insect, sucfi as 
is presented by the old cane surfaces between the several joints from 
which the roots have sprung in the cutting. It is even contended 
by some tliat the seedlings " come true " to the parent variety, to a 
very great extent. Wiiile the latter claim may be very gravely 
called in question, as contrary to all past experience, it may well be 
worth the while of the grape grower to give to his vines the addi- 
tional vigor and security afforded by their being seedlings instead of 
rooted cuttings, wiien intended as stocks for grafting. In other 
countries this practice is considered as involving a year's delay in 
the bearing of the vine. But at least as regards the wonderfully 
rapid-growing native wild vine of California, this may well be called 
in question. Seedlings grown from seed furnished by C. A. Wetmore, 
Esq., of kSan Francisco, who has given this subject very particular 
attention, to the University, have this season, eighteen hundred and 
eighty, between March and November, reached a height of twenty 
inches, and a thickness of as much as one half inch at the point 
above the root-crown where they will be grafted, next season, with 
scions of all the grape varieties most desirable for culture in Califor- 
nia. But wliether propagation by seed or cuttings shall prove the 
more desirable method, tfie Vitis Californica promises at this time a 
most satisfactory solution of the question of resistant stocks for tfie 
Vineyards of the Future. 



